1. Field of the Invention
The present invention relates to a semiconductor manufacturing apparatus, and more particularly, to a semiconductor manufacturing apparatus for resin encapsulation of a lead frame on which a semiconductor chip is mounted.
2. Description of the Related Art
In a related art for resin encapsulation of a lead frame having a semiconductor chip mounted thereon, the resin encapsulation of a semiconductor device is carried out by transfer molding. The lead frame, on which the semiconductor chip is mounted and is electrically connected to leads, is inserted between an upper mold and a lower mold. Then, the upper and lower molds are clamped, and a thermosetting resin, for example, is injected therebetween via a plunger. When the resin is filled into cavities formed in the upper and lower molds, respectively, and the resin is cured, the encapsulation of the semiconductor chip is completed. In the molds described above, in order to appropriately establish the positional relationship between the cavities and the lead frame, it is necessary to position the lead frame with respect to the upper and lower molds when inserted therebetween.
As a method of positioning the lead frame so as to mount the lead frame at an appropriate position on a mold, it is a typical way to fit a positioning pin provided at a predetermined position of a mold into a positioning hole formed in a peripheral portion of the lead frame (see Japanese Published Patent Application No. 10-86188 or 2001-7130).
Miniaturization of a semiconductor device along with miniaturization and densification of electronic equipment requires higher accuracy of positioning between a lead frame and a mold. However, in those related-art methods, for the purpose of preventing deformation of the positioning hole due to interference between the positioning pin and the positioning hole when the lead frame after the resin encapsulation is released from the molds, a predetermined clearance is indispensable to be secured between the positioning pin and the positioning hole, and this clearance is a cause of low accuracy of positioning the lead frame.
With regard to high accuracy positioning between the lead frame and the mold, for example, Japanese. Published Patent Application No. 10-86188 aims for, through adoption of a movable mechanism into the positioning pin, both improving the positioning accuracy by reducing the clearance and preventing deformation of the positioning hole. However, constructing the positioning pin so as to be movable complicates a structure of the mold, and the mechanism for moving the pin itself requires a clearance, resulting in a limit to the extent of the high accuracy. Further, there is a risk of a malfunction due to a flow of the resin into the clearance portion or the like.